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1.
Biomed Res Int ; 2019: 8043510, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31428646

RESUMEN

The aim was to analyze histologically the bone repair in a mandibular osteotomy model with different gaps between the segments. Nine male rabbits who underwent osteotomies on the mandibular body were fixed with a 1.5 system plate and no bone graft; group 1 (2 mm gap between segments), group 2 (5 mm gap between segments), and group 3 (8 mm gap between segments) were included. After 8 weeks they were euthanized and the sample was processed for histological analysis. Group 1 showed advanced bone repair with cartilaginous tissue and cancellous bone, showing osteoblasts and type III collagenous fibers. In group 2, a more delayed ossification was observed, with an extensive area of peripheral ossifying cartilage and chondrocytes in greater number at the center of the defect; group 3 showed no evidence of ossification with fibrous tissue, a very low level of chondrocytes, and some bone sequestrate. We can conclude that, in this animal model, 2 or 5 mm gap in the osteotomy could be repaired as bone when fixation is used. The size of the gap is an important factor for the use of bone grafts considering endochondral ossification. This model can be used for graft analysis and related technologies.


Asunto(s)
Placas Óseas , Trasplante Óseo , Mandíbula , Osteotomía Mandibular , Osteoblastos , Osteogénesis , Aloinjertos , Animales , Hueso Esponjoso/metabolismo , Hueso Esponjoso/patología , Hueso Esponjoso/cirugía , Humanos , Masculino , Mandíbula/metabolismo , Mandíbula/patología , Mandíbula/cirugía , Osteoblastos/metabolismo , Osteoblastos/patología , Conejos
2.
Molecules ; 24(16)2019 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-31426356

RESUMEN

Halitosis and submandibular abscesses are examples of mouth-related diseases with the possible bacterial origin. Salivary volatile organic compounds (VOCs) are potential biomarkers of them, once they can be addressed as metabolites of bacterial activity. Healthy patients (n = 15), subjects with submandibular abscesses located in fascial deep space (n = 10), and subjects with halitosis (n = 5) were enrolled in the study. Saliva samples were subjected to headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled to mass spectrometry (GC/MS) analysis. A total number of 164 VOCs was detected by the developed methodology, 23 specific for halitosis and 41 for abscess. Halitosis' profiles were characterized by a larger number of sulfur compounds, while for abscess they had a higher variety of alcohols, aldehydes, and hydrocarbons-biomarkers of inflammatory processes. Principal components analysis allowed visualization of clusters formed according to the evaluated conditions. Kruskal-Wallis test indicated that 39 VOCs presented differentiated responses between the studied groups, with statistical relevance (p < 0.05). Random forest was applied, and a prediction model based on eight VOCs (2-butanone, methyl thioacetate, 2-methylbutanoic acid, S-methyl pentanethioate, dimethyl tetrasulfide, indolizine, pentadecane, and octadecanal) provided 100% of sensitivity, 82% of specificity, and 91% of balanced accuracy, indicating the specific presence of submandibular abscess.


Asunto(s)
Absceso/diagnóstico , Alcoholes/aislamiento & purificación , Aldehídos/aislamiento & purificación , Halitosis/diagnóstico , Hidrocarburos/aislamiento & purificación , Compuestos de Azufre/aislamiento & purificación , Absceso/metabolismo , Absceso/patología , Adulto , Anciano , Alcoholes/clasificación , Aldehídos/clasificación , Biomarcadores/análisis , Estudios de Casos y Controles , Giro Dentado/metabolismo , Giro Dentado/patología , Diagnóstico Diferencial , Femenino , Cromatografía de Gases y Espectrometría de Masas , Halitosis/metabolismo , Halitosis/patología , Humanos , Hidrocarburos/clasificación , Masculino , Mandíbula/metabolismo , Mandíbula/patología , Persona de Mediana Edad , Análisis de Componente Principal , Saliva/química , Sensibilidad y Especificidad , Microextracción en Fase Sólida/métodos , Compuestos de Azufre/clasificación , Compuestos Orgánicos Volátiles
3.
ACS Appl Mater Interfaces ; 11(32): 28610-28620, 2019 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-31328910

RESUMEN

Advanced bone healing approaches included a wide range of biomaterials that mainly mimic the composition, structure, and properties of bone extracellular matrix with osteogenic activity. The present study aimed to develop a sandwich-like structure of electrospun nanofibers (NFs) based on polycaprolactone (PCL) and chitosan/polyethylene oxide (CS/PEO) composite to stimulate bone fracture healing. The morphology of the fabricated scaffolds was examined using scanning electron microscopy (SEM). Apatite deposition was evaluated using simulated body fluid (SBF). The physicochemical and mechanical properties of samples were analyzed by Fourier transform infrared, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and universal testing machine. SEM images exhibited a porous three-dimensional structure with NF diameters of 514-4745 nm and 68-786 nm for PCL NFs layer and the sandwich-like NFs scaffolds, respectively. Deposition of apatite crystal on scaffolds started at week 2 followed by heavy deposition at week 8. This was confirmed by measuring the consumption of calcium and phosphorous ions from SBF. Thermal stability of scaffolds was confirmed using DSC and TGA. Moreover, the PCL NF layer in the middle of the developed sandwich structure reinforced the scaffolds with bear load up to 12.224 ± 1.12 MPa and Young's modulus of 17.53 ± 3.24 MPa. The scaffolds' porous structure enhanced both cell propagation and proliferation. Besides, the presence of CS in the outer NF layers of the scaffolds increased the hydrophilicity, as evidenced by the reduction of contact angle from 116.6 to 57.6°, which is essential for cell attachment. Cell viability study on mesenchymal stem cells proved the cytocompatibility of the fabricated scaffolds. Finally, in vivo mandibular bone defect rabbit model was used to confirm the regeneration of a new healthy bone within 28 days. In conclusion, the developed scaffolds could be a promising solution to stimulate bone regeneration.


Asunto(s)
Regeneración Ósea , Mandíbula/metabolismo , Traumatismos Mandibulares/terapia , Nanofibras/química , Andamios del Tejido/química , Animales , Quitosano/química , Humanos , Masculino , Mandíbula/patología , Traumatismos Mandibulares/metabolismo , Traumatismos Mandibulares/patología , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/patología , Poliésteres/química , Polietilenglicoles/química , Conejos , Ratas
4.
Artif Cells Nanomed Biotechnol ; 47(1): 1577-1584, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31027424

RESUMEN

Bone tissue engineering is an area of regenerative medicine that attempts to repair bone defects. Seed cells such as dental pulp stem cells (DPSCs) and adipose tissue-derived stem cells (ADSCs) are two of the most well-characterized cells for bone regeneration because their use involves few ethical constraints and they have the ability to differentiate into multiple cell types, secreting growth factors and depositing mineral. However, bone regeneration ability of these cells remains unclear. This study aimed to compare the bone formation capacity of DPSCs and ADSCs in vitro and in vivo. Studies revealed that DPSCs had enhanced colony-forming ability, higher proliferative ability, stronger migration ability and higher expression of angiogenesis-related genes. They also secreted more vascular endothelial growth factor compared to ADSCs. In contrast, ADSCs grew more slowly compared to DPSCs but exhibited greater osteogenic differentiation potential, higher expression of osteoblast marker genes, and greater mineral deposition. Furthermore, after DPSCs and ADSCs were implanted into a mandibular defect of a rat for 6 weeks, ADSCs showed visible bone tissue as early as week 1 and promoted faster and greater bone regeneration compared to the DPSC group. These results suggest that ADSCs might be more useful than DPSCs for bone regeneration.


Asunto(s)
Tejido Adiposo/citología , Regeneración Ósea , Pulpa Dental/citología , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/citología , Animales , Calcificación Fisiológica , Diferenciación Celular , Proliferación Celular , Regulación de la Expresión Génica , Humanos , Mandíbula/citología , Mandíbula/metabolismo , Mandíbula/fisiología , Neovascularización Fisiológica , Osteogénesis , Ratas , Factor A de Crecimiento Endotelial Vascular/metabolismo
5.
Proc Natl Acad Sci U S A ; 116(14): 6954-6963, 2019 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-30886100

RESUMEN

Large mandibular defects are clinically challenging to reconstruct due to the complex anatomy of the jaw and the limited availability of appropriate tissue for repair. We envision leveraging current advances in fabrication and biomaterials to create implantable devices that generate bone within the patients themselves suitable for their own specific anatomical pathology. The in vivo bioreactor strategy facilitates the generation of large autologous vascularized bony tissue of customized geometry without the addition of exogenous growth factors or cells. To translate this technology, we investigated its success in reconstructing a mandibular defect of physiologically relevant size in sheep. We fabricated and implanted 3D-printed in vivo bioreactors against rib periosteum and utilized biomaterial-based space maintenance to preserve the native anatomical mandibular structure in the defect site before reconstruction. Nine weeks after bioreactor implantation, the ovine mandibles were repaired with the autologous bony tissue generated from the in vivo bioreactors. We evaluated tissues generated in bioreactors by radiographic, histological, mechanical, and biomolecular assays and repaired mandibles by radiographic and histological assays. Biomaterial-aided mandibular reconstruction was successful in a large superior marginal defect in five of six (83%) sheep. Given that these studies utilized clinically available biomaterials, such as bone cement and ceramic particles, this strategy is designed for rapid human translation to improve outcomes in patients with large mandibular defects.


Asunto(s)
Sustitutos de Huesos , Mandíbula , Traumatismos Mandibulares , Periostio , Impresión Tridimensional , Ingeniería de Tejidos , Animales , Reactores Biológicos , Femenino , Mandíbula/metabolismo , Mandíbula/patología , Traumatismos Mandibulares/metabolismo , Traumatismos Mandibulares/patología , Traumatismos Mandibulares/terapia , Periostio/metabolismo , Periostio/patología , Ovinos
6.
Congenit Anom (Kyoto) ; 59(2): 32-38, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29722137

RESUMEN

The aims of this study were to test whether the Y-chromosome and the autosomal dominant hemimelia (Dh) mutation can affect mandible morphology in mice. I analyzed mandible size and shape using landmark-based geometric morphometrics in 16 DH-Chr Y@ -+/+ (@ represents one of the inbred strain names) strains and observed significant differences in mandible size. The largest mandible was identified in strain DH-Chr YC3H and the smallest in strain DH-Chr YKK . Canonical variate and discriminant function analyses suggested that the mandible shapes of strains DH-Chr YC3H and DH-Chr YKK differed from those of the other strains. Because seven of the DH-Chr Y@ -+/+ strains were maintained with dominant hemimelia, I also analyzed the potential influence of dominant hemimelia on mandible morphology because dominant hemimelia is known to cause various skeletal malformations. There were no significant differences in mandible size in seven sets of DH-Chr Y@ -+/+ and DH-Chr Y@ -Dh/+ strains. However, canonical variate analysis mapped strains DH-Chr YCAS -Dh/+ and DH-Chr YCBA -Dh/+ mapped distantly from the rest. Additionally, I observed similar patterns of shape change between DH-Chr YCAS -+/+ and DH-Chr YCAS -Dh/+, and between DH-Chr YCBA -+/+ and DH-Chr YCBA -Dh/+. These data indicate that the Y-chromosome affects the size and shape of the mouse mandible. Dominant hemimelia affects mandible shape but not size, and its effects emerge depending on the kinds of Y-chromosomes.


Asunto(s)
Ectromelia/genética , Morfogénesis/genética , Mutación , Carácter Cuantitativo Heredable , Cromosoma Y/química , Animales , Animales Endogámicos , Mapeo Cromosómico , Ectromelia/patología , Genes Dominantes , Masculino , Mandíbula/anomalías , Mandíbula/anatomía & histología , Mandíbula/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Ratones Endogámicos CBA , Ratones Noqueados , Tamaño de los Órganos/genética , Sitios de Carácter Cuantitativo
7.
Environ Toxicol Chem ; 38(2): 460-463, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30525228

RESUMEN

A jaw lesion reported in mink exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and TCDD-like chemicals is considered a potential indicator of exposure to these chemicals. Many of the effects of TCDD-like chemicals are induced through interaction with the aryl hydrocarbon receptor. The present study indicates that mink dosed with ß-naphthoflavone, which is an aryl hydrocarbon receptor ligand but not a TCDD-like chemical, also develop the lesion. Environ Toxicol Chem 2019;38:460-463. © 2018 SETAC.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Mandíbula/efectos de los fármacos , Maxilar/efectos de los fármacos , Visón , beta-naftoflavona/toxicidad , Animales , Relación Dosis-Respuesta a Droga , Células Epiteliales/patología , Femenino , Ligandos , Mandíbula/metabolismo , Mandíbula/patología , Maxilar/metabolismo , Maxilar/patología , Receptores de Hidrocarburo de Aril/metabolismo
8.
Ann Anat ; 221: 38-47, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30240909

RESUMEN

Calcitonin gene-related peptide-α (CGRPα) is a neurotransmitter that is related to bone formation during development. However, CGRP expression is not well known to affect the formation of teeth during development. During tooth germ development, the relationships among CGRPα, calcitonin receptor-like receptor (CRLR), amelogenin (AMELX), dentin sialophosphoprotein (DSPP), osteopontin (OPN) and osteocalcin (OCN) are unclear despite various tooth and osteogenesis markers. Our real-time RT-PCR results showed that the expression levels of CGRPα mRNA gradually decreased, in contrast to the mRNA abundances of CRLR, AMELX, DSPP, OPN, and OCN, which rapidly increased from E14.5 to P1 in the mandible. In situ hybridization using an antisense probe for CGRPα mRNA showed significant localized expression levels around the tooth bud at E14.5 and epithelial cells near the dental ledge and outer and inner enamel epithelium at E17.5 compared to those at P1. The localization of the anti-CGRPα antibody reaction revealed a strong positive reaction at the surface layer of oral epithelial cells at E14.5 and oral epithelial cells of the dental lamina around the dental ledge depression in the mandible of E17.5 mice using immunohistochemical methods The different anti-CGRPα reaction revealed its important roles during tooth formation at the postnatal stage. CGRPα mRNA was also detected in the interactions of tooth germ with the formation of odontoblast and amelobast layers from dental papilla and inner enamel epithelium. CGRPα may also be related to tooth germ development. Furthermore, CGRPα is an important tooth and bone formation marker, and bone cells provide further evidence of a role in mandibular development in contrast to inflammatory systems.


Asunto(s)
Péptido Relacionado con Gen de Calcitonina/metabolismo , Mandíbula/metabolismo , Germen Dentario/metabolismo , Animales , Péptido Relacionado con Gen de Calcitonina/genética , Masculino , Mandíbula/crecimiento & desarrollo , Ratones , Ratones Endogámicos , Modelos Animales , ARN Mensajero/análisis , Reacción en Cadena en Tiempo Real de la Polimerasa , Germen Dentario/crecimiento & desarrollo
9.
Physiol Res ; 68(1): 135-140, 2019 03 06.
Artículo en Inglés | MEDLINE | ID: mdl-30433800

RESUMEN

Mammalian Meckel´s cartilage is a temporary structure associated with mandible development. Notably, its elimination is not executed by apoptosis, and autophagy was suggested as the major mechanism. Simultaneous reports point to pro-apoptotic caspases as novel participants in autophagic pathways in general. The aim of this research was to find out whether activation of pro-apoptotic caspases (-2, -3, -6, -7, -8 and -9) was associated with autophagy of the Meckel´s cartilage chondrocytes. Active caspases were examined in serial histological sections of mouse mandible using immunodetection and were correlated with incidence of autophagy based on Beclin-1 expression. Caspase-2 and caspase-8 were found in Beclin-1 positive regions, whereas caspase-3, -6, -7 and -9 were not present. Caspase-8 was further correlated with Fas/FasL and HIF-1alpha, potential triggers for its activation. Some Fas and FasL positivity was observed in the chondrocytes but caspase-8 activation was found also in FasL deficient cartilage. HIF-1alpha was abundantly present in the hypertrophic chondrocytes. Taken together, caspase-8 activation in the Meckel´s cartilage was demonstrated for the first time. Caspase-8 and caspase-2 were the only pro-apoptotic caspases detected in the Beclin-1 positive segment of the cartilage. Activation of caspase-8 appears FasL/Fas independent but may be switched on by HIF-1alpha.


Asunto(s)
Apoptosis/fisiología , Autofagia/fisiología , Cartílago Articular/metabolismo , Caspasas/metabolismo , Mandíbula/metabolismo , Animales , Cartílago Articular/citología , Humanos , Mandíbula/citología , Ratones
10.
Genesis ; 57(1): e23275, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30561090

RESUMEN

The mandibular or first pharyngeal arch forms the upper and lower jaws in all gnathostomes. A gene regulatory network that defines ventral, intermediate, and dorsal domains along the dorsal-ventral (D-V) axis of the arch has emerged from studies in zebrafish and mice, but the temporal dynamics of this process remain unclear. To define cell fate trajectories in the arches we have performed quantitative gene expression analyses of D-V patterning genes in pharyngeal arch primordia in zebrafish and mice. Using NanoString technology to measure transcript numbers per cell directly we show that, in many cases, genes expressed in similar D-V domains and induced by similar signals vary dramatically in their temporal profiles. This suggests that cellular responses to D-V patterning signals are likely shaped by the baseline kinetics of target gene expression. Furthermore, similarities in the temporal dynamics of genes that occupy distinct pathways suggest novel shared modes of regulation. Incorporating these gene expression kinetics into our computational models for the mandibular arch improves the accuracy of patterning, and facilitates temporal comparisons between species. These data suggest that the magnitude and timing of target gene expression help diversify responses to patterning signals during craniofacial development.


Asunto(s)
Regulación del Desarrollo de la Expresión Génica , Mandíbula/embriología , Transcriptoma , Animales , Tipificación del Cuerpo , Mandíbula/metabolismo , Ratones , Organogénesis , Pez Cebra
11.
Folia Biol (Praha) ; 64(3): 84-96, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30394266

RESUMEN

The purpose of the study was to test the hypothesis of different distribution spaces of elements in the rat mandibular bone and teeth. We used six adult males of Wistar laboratory rats for the study. After killing the animals, we extracted the molars and removed incisor crowns. The mandibular bone was divided into four parts (mesial-central-distal-ridge). Inductively coupled plasma mass spectrometry was used to determine the presence of 41 elements in the bone and tooth. Evidence of 14 elements was found in all samples (incisors-molarsbone). Generally, significant differences between the left and right side were found for K and Rb in the bone locations. As regards statistically significant differences in incisors-molars-bone locations, the elements for which these differences were found for all comparisons are listed as incisors versus individual molars, incisors versus bone locations, and individual molars versus bone locations: a) incisors-molars: Ba, Mn, Mo, Sr, Zn, K, Mg and Rb; b) incisors-bone: Fe, K, Mg, Mn, Na, Zn and Ba; c) molars-bone: Mn, Mo, Na and Mg. Statistically significant differences were also found between molars for Fe, Mg, Mn, and Sr and between bone locations for Ba, Ca, Mn, Sr, K, Rb, Zn, Mo, Mg, and Na. The elements Cu, Ni and Co were without pronounced differences. Twenty-seven elements were below the detection limit. Our results indicate different distributions of some elements in the rat mandibular incisors-molars-bone. We assume that the knowledge of chemical element contents in the laboratory rat bone and teeth will prove useful in experimental research of both these hard tissues.


Asunto(s)
Elementos , Mandíbula/metabolismo , Diente/metabolismo , Análisis de Varianza , Animales , Masculino , Ratas Wistar
12.
Int J Immunopathol Pharmacol ; 32: 2058738418798249, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30350738

RESUMEN

The purpose of the study was to perform an immunohistochemical and histological evaluation of samples taken from different bone regeneration procedures in atrophic human mandible. 30 patients (15 men and 15 women, age range of 35-60 years), non-smokers, with good general and oral health were recruited in this study and divided into three groups. The first group included patients who were treated with blood Concentration Growth Factors (bCGF), the second group included patients who were treated with a mixture of bCGF and autologous bone, while the third group of patients was treated with bCGF and tricalcium phosphate/hydroxyapatite (TCP-HA). Six months after the regenerative procedures, all patients undergone implant surgery, and a bone biopsy was carried out in the site of implant insertion. Each sample was histologically and immunohistochemically examined. Histological evaluation showed a complete bone formation for group II, partial ossification for group I, and moderate ossification for group III. Immunohistochemical analysis demonstrated a statistically significant difference between the three groups, and the best clinical result was obtained with a mixture of bCGF and autologous bone.


Asunto(s)
Remodelación Ósea/efectos de los fármacos , Trasplante Óseo , Hidroxiapatitas/uso terapéutico , Inmunohistoquímica , Péptidos y Proteínas de Señalización Intercelular/uso terapéutico , Mandíbula/efectos de los fármacos , Mandíbula/cirugía , Enfermedades Mandibulares/terapia , Adulto , Atrofia , Biopsia , Implantación Dental , Europa (Continente) , Femenino , Humanos , Masculino , Mandíbula/metabolismo , Mandíbula/patología , Enfermedades Mandibulares/metabolismo , Enfermedades Mandibulares/patología , Persona de Mediana Edad , Estudios Prospectivos , Factores de Tiempo , Trasplante Autólogo , Resultado del Tratamiento
13.
Arch Oral Biol ; 96: 195-200, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30292055

RESUMEN

The alveolar bone has a unique capacity to follow the teeth's movements. It is formed around erupting teeth and their periodontal ligaments: the more the teeth have erupted, the larger the alveolar process. Throughout life the teeth erupt and migrate in an occlusal and mesial direction to compensate for attrition, an evolutionary trait. After tooth extraction, the alveolar process is resorbed to varying degrees. The mandibular alveolar bone mirrors skeletal bone condition. Due to fast bone turnover (which is the fastest in the whole skeleton), low bone mass and increased fracture risk may first be seen here. If a periapical radiograph of the mandibular premolars shows a dense trabeculation with well-mineralized trabeculae and small intertrabecular spaces, it is a reliable sign of normal skeletal bone density (BMD) and low skeletal fracture risk, whereas a sparse trabecular pattern indicates osteopenia and high fracture risk. The bone turnover rate in the mandible is twice that of the maxilla, and may, hypothetically, play a role in the development of osteonecrosis of the jaw (ONJ), which has been found mainly in the mandibular alveolar process?


Asunto(s)
Proceso Alveolar/fisiología , Mandíbula/fisiología , Proceso Alveolar/metabolismo , Animales , Biomarcadores/metabolismo , Fenómenos Biomecánicos/fisiología , Osteonecrosis de los Maxilares Asociada a Difosfonatos/fisiopatología , Densidad Ósea/fisiología , Remodelación Ósea/fisiología , Humanos , Mandíbula/metabolismo , Osteoporosis/fisiopatología , Erupción Dental/fisiología , Extracción Dental , Técnicas de Movimiento Dental
14.
Dent Med Probl ; 55(1): 11-16, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30152629

RESUMEN

BACKGROUND: Sofosbuvir is a nucleotide compound that has proved to be among the most potent orally available antiviral treatments. Infrequent but serious adverse events have been reported with the use of oral nucleos(t)ide analogues. OBJECTIVES: Investigating sofosbuvir-induced alterations in the rat mandibular alveolar process. MATERIAL AND METHODS: In the study, 30 adult male albino rats were used and divided randomly into following groups: group 1, group 2 and group 3 (10 rats per group). Group 1 served as a control, group 2 received sofosbuvir through oral gavage at a dose of 40 mg/kg/day for 6 weeks, and group 3 was similar to group 2 but received sofosbuvir for 12 weeks. The animals were sacrificed at the end of the experiment. The mandibles were dissected and examined histologically as well as by scanning electron microscope (SEM) and energy dispersive X-ray unit (EDX). RESULTS: Histologically, group 1 showed normal alveolar process. In group 2, histopathological changes occurred as bone trabeculae demonstrated obvious Howship's lacuna of osteoclasts. In group 3, bone trabeculae exhibited multiple degenerated areas as well as apparent vacuolization. Scanning electron microscopic examination revealed smooth alveolar bone architecture in group 1. On the other hand, groups 2 and 3 demonstrated irregular bone architecture with formation of multiple pores. EDX analysis demonstrated the highest calcium concentration in the control group, while the lowest was found in group 3. Statistical analysis of the EDX results revealed a statistically significant difference among the studied groups as the p-value was <0.01. CONCLUSIONS: It has been concluded that sofosbuvir induced apparent alterations in the rats' alveolar bone. This effect was exaggerated in a longer period of drug administration. The sofosbuvir-induced alterations might be attributed mainly to mitochondrial toxicity. The effect had been clearly shown histologically and morphologically as well as in bone mineral (calcium) content.


Asunto(s)
Proceso Alveolar/patología , Antivirales/administración & dosificación , Sofosbuvir/administración & dosificación , Proceso Alveolar/metabolismo , Animales , Antivirales/efectos adversos , Calcio/metabolismo , Hueso Esponjoso/patología , Esquema de Medicación , Mandíbula/metabolismo , Mandíbula/patología , Microscopía Electrónica de Rastreo , Modelos Animales , Ratas , Sofosbuvir/efectos adversos , Espectrometría por Rayos X
15.
J Oral Maxillofac Surg ; 76(12): 2540-2550, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30102877

RESUMEN

PURPOSE: A major advantage of guided implant surgery using 3-dimensionally printed guides is the ability to perform accurate flapless surgery. A drawback of a flapless technique is the inability to manipulate soft tissue to ensure sufficient gingiva around the implant. The purpose of this study was to determine how often flapless surgery using surgical guides results in less than 2 mm of keratinized tissue surrounding the implant. MATERIALS AND METHODS: This retrospective analysis included 27 maxillary and 27 mandibular implant sites that underwent treatment planning for implant-guided surgery using 3Shape Implant Studio (3Shape, Copenhagen, Denmark). Intraoral scan images were used to measure the width of the keratinized tissue on the buccal aspect of each implant site in both arches and the lingual aspect in the mandibular arch. Three examiners measured the amount of buccal and lingual keratinized tissue in millimeters at each implant site. Analysis of variance (P < .05) and correlation coefficients were used to determine statistically significant differences in keratinized tissue among sites. RESULTS: No statistically significant difference was found either between the widths of buccal keratinized tissue in the maxillary anterior (4.06 ± 1.42 mm) and posterior (4.93 ± 2.54 mm) areas (P = .293) or between the amounts of buccal and lingual keratinized tissue in the mandible (P = .995). The keratinized tissue width in the maxillary buccal area was significantly different (4.48 ± 2.04 mm) from that in the mandibular posterior buccal (1.98 ± 1.41 mm) and lingual (1.98 ± 1.23 mm) areas (P < .001). Over 77% of maxillary implant sites had greater than 3 mm of gingiva, and just over 20% had sufficient gingiva in the mandible. CONCLUSIONS: Adequate keratinized tissue was found in most of the planned maxillary implant sites, whereas most of the mandibular posterior implant sites had inadequate keratinized tissue. Therefore, elevation of a flap to preserve and reposition existing keratinized tissue around implants should be considered when planning to use tooth-borne surgical guides in the posterior mandible.


Asunto(s)
Implantación Dental Endoósea/métodos , Implantes Dentales , Mandíbula/cirugía , Maxilar/cirugía , Cirugía Asistida por Computador/métodos , Biomarcadores/metabolismo , Estudios de Casos y Controles , Implantación Dental Endoósea/instrumentación , Humanos , Queratinas/metabolismo , Mandíbula/metabolismo , Mandíbula/patología , Maxilar/metabolismo , Maxilar/patología , Variaciones Dependientes del Observador , Estudios Retrospectivos , Cirugía Asistida por Computador/instrumentación , Colgajos Quirúrgicos
16.
Acta Biomater ; 76: 275-282, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29898419

RESUMEN

A considerable amount of research has focused on improving regenerative therapy strategies for repairing defects in load-bearing bones. The enhancement of tissue regeneration with microRNAs (miRNAs) is being developed because miRNAs can simultaneously regulate multiple signaling pathways in an endogenous manner. In this study, we developed a miR-210-based bone repair strategy. We identified a miRNA (miR-210-3p) that can simultaneously up-regulate the expression of multiple key osteogenic genes in vitro. This process resulted in enhanced bone formation in a subcutaneous mouse model with a miR-210-3p/poly-l-lactic acid (PLLA)/bone marrow-derived stem cell (BMSC) construct. Furthermore, we constructed a model of critical-sized load-bearing bone defects and implanted a miR-210-3p/ß-tricalcium phosphate (ß-TCP)/bone mesenchymal stem cell (BMSC) construct into the defect. We found that the load-bearing defect was almost fully repaired using the miR-210-3p construct. We also identified a new mechanism by which miR-210-3p regulates Sclerostin protein levels. This miRNA-based strategy may yield novel therapeutic methods for the treatment of regenerative defects in vital load-bearing bones by utilizing miRNA therapy for tissue engineering. STATEMENT OF SIGNIFICANCE: The destroyed maxillofacial bone reconstruction is still a real challenge for maxillofacial surgeon, due to that functional bone reconstruction involved load-bearing. Base on the above problem, this paper developed a novel miR-210-3p/ß-tricalcium phosphate (TCP)/bone marrow-derived stem cell (BMSC) construct (miR-210-3p/ß-TCP/BMSCs), which lead to functional reconstruction of critical-size mandible bone defect. We found that the load-bearing defect was almost fully repaired using the miR-210-3p construct. In addition, we also found the mechanism of how the delivered microRNA activated the signaling pathways of endogenous stem cells, leading to the defect regeneration. This miRNA-based strategy can be used to regenerate defects in vital load-bearing bones, thus addressing a critical challenge in regenerative medicine by utilizing miRNA therapy for tissue engineering.


Asunto(s)
Proteínas Morfogenéticas Óseas/biosíntesis , Mandíbula , Traumatismos Mandibulares , MicroARNs , Osteogénesis/efectos de los fármacos , Trasplante de Células Madre , Células Madre , Animales , Perros , Mandíbula/metabolismo , Mandíbula/patología , Traumatismos Mandibulares/metabolismo , Traumatismos Mandibulares/patología , Traumatismos Mandibulares/terapia , Ratones , MicroARNs/química , MicroARNs/farmacocinética , MicroARNs/farmacología , Células Madre/metabolismo , Células Madre/patología , Soporte de Peso
17.
Angle Orthod ; 88(5): 624-631, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29708397

RESUMEN

OBJECTIVES: To investigate the individual and synergistic effects of growth hormone (GH) and functional appliance (FA) on mandibular growth in an adolescent rat model. MATERIALS AND METHODS: Forty adolescent (6-week-old) female Wistar rats were randomly divided into four groups (10 rats in each group). The control group received a sham treatment (intra-abdominal injection of phosphate-buffered saline), the GH group received an intra-abdominal injection of recombinant human growth hormone, the FA group was treated with a mandibular advancement device, and the GH+FA group received both the GH and FA treatments. The amount of mandibular growth in each group was measured quantitatively using cone-bean computed tomography. The growth of condylar cartilage and expression of matrix metalloproteinases-1 and -13 (MMP-1 and MMP-13) and type II and X collagen (Col II and Col X) were assessed using histological staining and immunostaining techniques. RESULTS: After 4 weeks, there was significant mandibular growth in the FA group compared with the control group ( P < .05). The GH+FA group had significantly greater mandibular length, thickness of condylar cartilage, and expression of MMP-1, MMP-13, Col II, and Col X in the cartilage than the other groups ( P < .05). The GH+FA group and GH group had significantly greater weight than the FA and control groups ( P < .05). CONCLUSIONS: The FA as well as GH+FA stimulated mandibular growth in adolescent rats.


Asunto(s)
Hormona del Crecimiento/farmacología , Mandíbula/crecimiento & desarrollo , Animales , Colágeno Tipo II/metabolismo , Colágeno Tipo X/metabolismo , Tomografía Computarizada de Haz Cónico , Femenino , Mandíbula/diagnóstico por imagen , Mandíbula/efectos de los fármacos , Mandíbula/metabolismo , Metaloproteinasa 1 de la Matriz/metabolismo , Metaloproteinasa 13 de la Matriz/metabolismo , Aparatos Ortodóncicos Funcionales , Ratas , Ratas Wistar
18.
Sci Rep ; 8(1): 7701, 2018 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-29799016

RESUMEN

Social cohesion in social insect colonies can be achieved through the use of chemical signals whose production is caste-specific and regulated by social contexts. In honey bees, queen mandibular gland pheromones (QMP) maintain reproductive dominance by inhibiting ovary activation and production of queen-like mandibular gland signals in workers. We investigated whether honey bee queens can control reproductively active workers of the intraspecific social parasite Apis mellifera capensis, parasitising A. m. scutellata host colonies. Our results show that the queen's QMP suppresses ovarian activation and inhibits the production of QMP pheromone signals by the parasitic workers, achieved through differential expression of enzymes involved in the biosynthesis of these pheromones at two points in the biosynthetic pathway. This is the first report showing that honey bee queens can regulate reproduction in intraspecific social parasites and deepens our understanding of the molecular mechanisms involved in the regulation of worker reproduction in social insects.


Asunto(s)
Abejas/fisiología , Conducta Competitiva/fisiología , Dominación-Subordinación , Mandíbula/metabolismo , Glándulas Odoríferas/metabolismo , Conducta Sexual Animal/fisiología , Animales , Secreciones Corporales/fisiología , Femenino , Masculino , Feromonas/metabolismo , Reproducción/fisiología , Conducta Social , Predominio Social , Simbiosis/fisiología
19.
J Bone Miner Res ; 33(8): 1520-1531, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29624728

RESUMEN

Estrogens play an important role in bone growth and maturation as well as in the regulation of bone turnover in adults. Although the effects of 17ß-estradiol (E2) are well documented in long bones and vertebrae, little is known regarding its action in the mandible. E2 actions could be mediated by estrogen receptor (ER) α or ß. ERs act primarily as transcriptional factors through two activation functions (AFs), AF1 and AF2, but they can also elicit membrane-initiated steroid signaling (MISS). The aim of the present study was to define ER pathways involved in E2 effects on mandibular bone. Using mice models targeting ERß or ERα, we first show that E2 effects on mandibular bone are mediated by ERα and do not require ERß. Second, we show that nuclear ERαAF2 is absolutely required for all the actions of E2 on mandibular bone. Third, inactivation of ERαMISS partially reduced the E2 response on bone thickness and volume, whereas there was no significant impact on bone mineral density. Altogether, these results show that both nuclear and membrane ERα are requested to mediate full estrogen effects in the mandible of growing mice. Finally, selective activation of ERαMISS is able to exert an effect on alveolar bone but not on the cortical compartment, contrary to its protective action on femoral cortical bone. To conclude, these results highlight similarities but also specificities between effects of estrogen in long bones and in the mandible that could be of interest in therapeutic approaches to treat bone mass reduction. © 2018 American Society for Bone and Mineral Research.


Asunto(s)
Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Receptor alfa de Estrógeno/metabolismo , Mandíbula/metabolismo , Animales , Hueso Esponjoso/diagnóstico por imagen , Hueso Esponjoso/efectos de los fármacos , Membrana Celular/efectos de los fármacos , Núcleo Celular/efectos de los fármacos , Hueso Cortical/diagnóstico por imagen , Hueso Cortical/efectos de los fármacos , Estradiol/farmacología , Receptor beta de Estrógeno/metabolismo , Mandíbula/efectos de los fármacos , Ratones Endogámicos C57BL , Microtomografía por Rayos X
20.
J Vis Exp ; (133)2018 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-29658923

RESUMEN

Enamel defects resulting from environmental conditions and ways of life are public health concerns because of their high prevalence. These defects result from altered activity of cells responsible for enamel synthesis named ameloblasts, which present in enamel organ. During amelogenesis, ameloblasts follow a specific and precise sequence of events of proliferation, differentiation, and death. A rat continually growing incisors is a suitable experimental model to study ameloblast activity and differentiation stages in physiological and pathological conditions. Here, we describe a reliable and consistent method to micro-dissect enamel organ of rats exposed to environmental toxicants. The micro-dissected dental epithelia contain secretion- and maturation-stage ameloblasts that may be used for qualitative experiments, such as immunohistochemistry assays and in situ hybridization, as well as for quantitative analyses such as RT-qPCR, RNA-seq, and Western blotting.


Asunto(s)
Órgano del Esmalte/metabolismo , Sustancias Peligrosas/efectos adversos , Incisivo/metabolismo , Mandíbula/metabolismo , Animales , Órgano del Esmalte/patología , Incisivo/patología , Masculino , Mandíbula/patología , Ratas
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